OS.rar_动态分区分配

// ManegmentOfMemory.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include "iostream.h" #include "stdlib.h" #include "time.h" #include "ios.h" #include "iomanip.h" #define FINISH 0 #define RUN 1 #define WAITE 2 //#define NULL 0 typedef struct memory//内存块 { int m_begin; int m_size; memory *next; }memory; typedef struct mLNode { //int m_num; int m_total; memory *next; }mLNode; typedef struct pcb { int p_size; int status; int pbegin; //pcb *next; }pcb; /*typedef struct pLNode{ int p_num; pcb *next; }pLNode;*/ void DisplaymLNode(); void Displayg_pcb(); bool m_FirstFit();//用最先适用算法来进行内存的分配 bool InitialMemory(); bool InitialProcessing(); bool Getg_pro();//随机得到进程的数目 bool m_Recycle(pcb *p);//用于对释放内存的回收 int g_pro;//总的进程数 int g_mem;//总的内存数 unsigned long next = 1;//来产生随机数 mLNode g_mLNode;//未使用的内存块链表 pcb *g_pcb;//进程链表 //pLNode g_pLNode; void srand(unsigned int seed) { next = seed; } int rand() { next = next * 1103515245 + 12345; return (unsigned int)(next / 65536)%32768; } //初始各个进程，是由随机函数来进行实现的;并且每个进程的大小限制在10~400之间 bool InitialProcessing() { g_pcb = new pcb[g_pro]; int msize; for(int i=0;i<g_pro;i++) { //随机产生进程所需空间 //srand( g_pcb[i-1].p_size ); while((msize = rand()%700) < 400 || (msize = rand()%700) > 600); g_pcb[i].p_size = msize; g_pcb[i].status = WAITE; } return true; } //初始化未分配出去的内存块的链表 bool InitialMemory() { srand( (unsigned)time( NULL ) ); int msize; while((msize = rand()%2000) < 900 ); g_mem = msize; g_mLNode.m_total = msize; //开始时内存还没有分配故总的数目为1且空闲为所刚产生的内存的大小 g_mLNode.next = (memory *)malloc(msize*sizeof(memory)+1); g_mLNode.next->next = NULL; //刚建立时next应该指向为空 g_mLNode.next->m_begin = 1 ; g_mLNode.next->m_size = msize; return true; } //随机产生进程的个数并且控制进程的数目在5~12之间 bool Getg_pro() { srand( (unsigned)time( NULL ) ); while((g_pro = rand() % 100) < 5 || (g_pro > 8)); cout <<"本次程序所模拟的进程的个数： "<< g_pro-1 <<endl; //cout <<"请输入任意大的一个数来产生随机数：" cout << "提示：在表示进程状态时 0---->完 成" <<endl << " 1---->正在执行" <<endl << " 2---->就 绪" <<endl; return true; } //用最先适用算法来实现内存的分配 bool m_FirstFit() { memory *m,*prem;//记录当前和前一次走过的空闲块 m = g_mLNode.next ; prem = m; for (int i=1 ;i<=g_pro ;i++){ if (g_pcb[i].status == RUN || g_pcb[i].status == FINISH) continue; while (m!=NULL){ if (m->m_size >= g_pcb[i].p_size ){//满足进程对内存的需求 if (m->m_size == g_pcb[i].p_size){ g_mLNode.m_total -= g_pcb[i].p_size ; g_pcb[i].pbegin = m->m_begin ; prem->next = m->next ; g_pcb[i].status = RUN; } else{ g_mLNode.m_total = g_mLNode.m_total - g_pcb[i].p_size ; g_pcb[i].pbegin = m->m_begin ; m->m_begin = m->m_begin + g_pcb[i].p_size; m->m_size -= g_pcb[i].p_size ; g_pcb[i].status = RUN; } break;//分配成功就跳出来 } else{ prem = m; m = m->next ; } } } return true; }//m_FirstFit //来管理内存的回收以及对上下空闲块的合并 bool m_Recycle(pcb *p) { memory *m,*prem,*mpcb; mpcb = (memory *)malloc(sizeof(memory)); mpcb->next = NULL; m = g_mLNode.next ;//指向第一个未分配的内存块 prem = m; if (p->status == FINISH || p->status == WAITE) return false; mpcb->m_begin = p->pbegin ; mpcb->m_size = p->p_size ; int size = p->p_size ; int end = mpcb->m_begin + size - 1;//记录该进程块的始未地址和大小 p->p_size = 0; p->pbegin = 0; p->status = FINISH;//释放进程所占有的资源 g_mLNode.m_total += size;//更新未分配的内存总数 //回收内存，将释放内存与其相邻的空闲块相合并得到一个新的空闲内存块，准备将其放入到链表中 while ( m!=NULL ){ if (mpcb->m_begin == m->m_begin + m->m_size ){//空闲在左边 m->m_size = m->m_size +mpcb->m_size ; mpcb = m; //prem = m; //m = m->next ; break; } else if (end == m->m_begin - 1){//空闲块在右边 mpcb->m_size += m->m_size ; //prem = m; //m = m->next ; break; } else { prem = m; m = m->next ; } }//while m = g_mLNode.next ; prem = m; while ( m!=NULL && (mpcb->m_begin > m->m_begin) ){ prem = m; m = m->next ; } if (prem == m && m == g_mLNode.next ) { if ( m->m_begin == mpcb->m_begin) g_mLNode.next = mpcb; else{ g_mLNode.next = mpcb; mpcb->next = m; } } else { mpcb->next = m ; prem->next = mpcb; } return true; } //显示各个进程的现况 void Displayg_pcb() { cout <<"\n\n" <<endl; cout << "此进各个进程的状态为：" << endl; cout << "进程号\t所需内存\t进程状态" << endl; for(int i=1 ;i<g_pro ;i++){ cout << i << "\t" << g_pcb[i].p_size << "\t\t" << g_pcb[i].status << endl; } } void DisplaymLNode() { memory *m = g_mLNode.next; cout <<"内存大小："<< g_mem << endl; cout <<"剩余内存："<< g_mLNode.m_total <<endl; int i=1; while(m!=NULL) { cout <<"第"<<i<<"块空闲块 "; cout <<"起始地址:"<< m->m_begin <<" 大小:"<< m->m_size << endl;//" 末尾地址:"<< m->m_begin + m->m_size -1 <<endl; m = m->next ; i++; } } void main() { Getg_pro();//获取作业数 InitialProcessing(); InitialMemory(); Displayg_pcb(); DisplaymLNode(); m_FirstFit(); Displayg_pcb(); DisplaymLNode(); for (int j=1 ;j<=g_pro ;j++) { m_Recycle(&g_pcb[j]); m_FirstFit(); Displayg_pcb(); DisplaymLNode(); } }